[ilamont]

These lists can be manipulated. There was a case a few years back involving bogus bookstore sales of Lani Sarem’s "Handbook for Mortals" to trick the New York Times:

Stamper and other YA writers, including Jeremy West, began to investigate. Stamper shared messages he had received from bookshop staff who said they had been contacted to see if their store was an NYT-reporting shop – the paper’s lists are collated from information supplied by a confidential group of stores – before a bulk order was placed. Another bookshop shared similar information with West, while Publishers Weekly reported that a shop outside Las Vegas had a customer who ordered 87 copies after learning it was an NYT-reporting shop.

(Source: https://www.theguardian.com/books/2017/aug/25/handbook-for-m...)

I'm also skeptical of data from Amazon, whose KDP Select/Kindle Unlimited ebook platform is notorious for scams designed to ensure rank or extra payouts for authors. See http://www.annchristy.com/ku-scammers-on-amazon-what-you-nee... for an explanation of how one scam worked, and the HN discussion: https://news.ycombinator.com/item?id=11520212.

[rosser]

A friend used to work for an organization whose function was to buy books from NYT-reporting sellers for purposes of inflating the sales numbers of a given title, to manipulate it onto the bestseller list. They were usually paid by the publishers, but sometimes directly by the authors themselves.

This has been going on for a very long time.

EDIT: Phrasing.

[rsj_hn]

WOW, can I ask what the most common genre was?

[rosser]

I didn't ask, but in the conversations we had on the topic, I never got the sense that was a thing that mattered to them.